Contoocook Railroad Bridge
Encyclopedia
The Contoocook Railroad Bridge is a covered bridge
on the former Contoocook Valley (first Concord & Claremont, later Boston & Maine) Railroad line spanning the Contoocook River
in the center of the village of Contoocook, New Hampshire
. It is referred to in the National Register of Historic Places
as the Hopkinton Railroad Covered Bridge, for the town of Hopkinton, New Hampshire
, in which the village of Contoocook is located.
Built in 1889 to replace a lighter covered railroad bridge of unknown date, having been built by the former Concord and Claremont Railroad (acquired by the Boston & Maine Railroad in 1887), the bridge is the oldest of four surviving double-web Town lattice railroad bridges, and is the oldest extant covered railroad bridge in the United States
. (The others double Towns are Pier Bridge, Newport, New Hampshire
, 1907; Wright’s Bridge, Newport, NH, 1906; and Fisher Bridge, Stowe, Vermont
, 1908.) It was probably designed by Boston & Maine Railroad engineer Jonathan Parker Snow (1848–1933) and built by carpenter David Hazelton (1832–1908). Under Snow, the Boston & Maine utilized wooden bridges on its branch lines longer than any other major railroad, the last of these constructed in 1916. The nearby depot was built in 1850 on the earlier Concord & Claremont Railroad.
The bridge presents the clearest, most original structure of its type, as the others incorporate significant structural modifications. The main truss
es are double Town lattice and are continuous over a central pier
to form two spans of approximately 71 feet (21.6 m) each. It has been often said they were built by the mile and cut off by the yard
. The center pier is skewed to match the river flow, as are the abutment
s. This is because the bridge spans the river on a bias.
The bridge was in use as a railroad bridge until 1962, survived a flood in 1936, a hurricane in 1938, and was moved off its foundations twice during its lifespan and saved from being completely washed down river by the rail tracks running through it. Following its railroad service, it functioned as a warehouse between 1962 and 1990. In 2006 the bridge saw minor structural repairs to its bottom chord at the upstream north corner, the bolsters were replaced for the first time since the hurricane of 1938, and the bed timbers were replaced by granite pedestals. The work was paid for by a donation from the National Society for the Preservation of Covered Bridges. Recently the bridge underwent slight alterations being completed mid-winter 2009-2010 which consisted of a dry-head, open pipe sprinkler system for the bridge interior with exterior fire department connection, including linear heat detectors, fire alarm system, fire retardant coating and LED motion sensor lighting inside the bridge at an approximate cost of $123,300 paid for and engineered by the New Hampshire Department of Transportation
.
Covered bridge
A covered bridge is a bridge with enclosed sides and a roof, often accommodating only a single lane of traffic. Most covered bridges are wooden; some newer ones are concrete or metal with glass sides...
on the former Contoocook Valley (first Concord & Claremont, later Boston & Maine) Railroad line spanning the Contoocook River
Contoocook River
The Contoocook River is a river in New Hampshire. It flows from Pool Pond and Contoocook Lake on the Jaffrey/Rindge border to Penacook , where it empties into the Merrimack River. It is one of only a few rivers in New Hampshire that flow in a predominantly northward direction...
in the center of the village of Contoocook, New Hampshire
Contoocook, New Hampshire
Contoocook is a village and census-designated place within the town of Hopkinton in Merrimack County, New Hampshire, United States. The population was 1,444 at the 2010 census.-History:...
. It is referred to in the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
as the Hopkinton Railroad Covered Bridge, for the town of Hopkinton, New Hampshire
Hopkinton, New Hampshire
Hopkinton is a town in Merrimack County, New Hampshire, United States. The population was 5,589 at the 2010 census. It consists of three villages: Hopkinton, West Hopkinton, and Contoocook...
, in which the village of Contoocook is located.
Built in 1889 to replace a lighter covered railroad bridge of unknown date, having been built by the former Concord and Claremont Railroad (acquired by the Boston & Maine Railroad in 1887), the bridge is the oldest of four surviving double-web Town lattice railroad bridges, and is the oldest extant covered railroad bridge in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. (The others double Towns are Pier Bridge, Newport, New Hampshire
Newport, New Hampshire
Newport is a town in and the county seat of Sullivan County, New Hampshire, United States. It is west-northwest of Concord. The population was 6,507 at the 2010 census. A covered bridge is in the northwest...
, 1907; Wright’s Bridge, Newport, NH, 1906; and Fisher Bridge, Stowe, Vermont
Stowe, Vermont
Stowe is a town in Lamoille County, Vermont, United States. The population was 4,339 at the 2000 census. Tourism is a significant industry.-Geography:...
, 1908.) It was probably designed by Boston & Maine Railroad engineer Jonathan Parker Snow (1848–1933) and built by carpenter David Hazelton (1832–1908). Under Snow, the Boston & Maine utilized wooden bridges on its branch lines longer than any other major railroad, the last of these constructed in 1916. The nearby depot was built in 1850 on the earlier Concord & Claremont Railroad.
The bridge presents the clearest, most original structure of its type, as the others incorporate significant structural modifications. The main truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...
es are double Town lattice and are continuous over a central pier
Pier
A pier is a raised structure, including bridge and building supports and walkways, over water, typically supported by widely spread piles or pillars...
to form two spans of approximately 71 feet (21.6 m) each. It has been often said they were built by the mile and cut off by the yard
Yard
A yard is a unit of length in several different systems including English units, Imperial units and United States customary units. It is equal to 3 feet or 36 inches...
. The center pier is skewed to match the river flow, as are the abutment
Abutment
An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...
s. This is because the bridge spans the river on a bias.
The bridge was in use as a railroad bridge until 1962, survived a flood in 1936, a hurricane in 1938, and was moved off its foundations twice during its lifespan and saved from being completely washed down river by the rail tracks running through it. Following its railroad service, it functioned as a warehouse between 1962 and 1990. In 2006 the bridge saw minor structural repairs to its bottom chord at the upstream north corner, the bolsters were replaced for the first time since the hurricane of 1938, and the bed timbers were replaced by granite pedestals. The work was paid for by a donation from the National Society for the Preservation of Covered Bridges. Recently the bridge underwent slight alterations being completed mid-winter 2009-2010 which consisted of a dry-head, open pipe sprinkler system for the bridge interior with exterior fire department connection, including linear heat detectors, fire alarm system, fire retardant coating and LED motion sensor lighting inside the bridge at an approximate cost of $123,300 paid for and engineered by the New Hampshire Department of Transportation
New Hampshire Department of Transportation
The State of New Hampshire Department of Transportation is a government agency of the U.S. state of New Hampshire. The NHDOT is under the executive direction of Commissioner of Transportation George Campbell. The main office of the NHDOT is located in the J.O...
.